Sound recording and reproducing machine



7 1,618,888 H. A. ROGERS 0m RECORDING AND REPRODUCING MACHINE Feb. 22, 19 21.

' Filed Jan. 1924 m yew roR HAROL 0 A. ROfi-EKS HIS ATTORNEY.

l atented Feb. 22, 1927.

UNITED STATES 1,618,888 PATENT OFFICE.

SOUND RECORDING AND REPRODUCING MACHINE.

Application filed January 31, 1924, Serial No. 689,744, and in Great Britain January 31, 1923.

This invention relates to sound recording and reproducing machines of the kind which give to the disc records an approximately constant linear velocity of needle groove or track past the needle as distinct from a constant rotary speed or angular velocity such as is required for ordinary discs.

Machines of the kind referred to have been suggested wherein the speed of the turntable or record is controlled by a gover nor mechanism operated preferably through bevel gearing by a rubber-tyred wheel in frictional contact with said turntable or record and in substantially tangential alignment with the stylus, said governor and wheel being mounted in a frame or asing and so connected with the tone-arm intermediately between the pivot thereof and the sound-box that the wheel moves with the stylus across the record.

The present invention provides for attachment to the sound-box of the machines referred to, of a rolling spe-ed'control wherein a rolling member consisting of one or more wheels or rollers, makes contact directly or indirectly with the record track and is connected by a helical drive with a governor of the revolving Weight type, the whole being mounted in a frame or partial- 1y enclosed in a box which is hinged horizontally and vertically to the sound box and connected by a guide rod to a pivot on the tone-arm standard or casing so that the rolling member, resting on the record directly or indirectly through an intermediate band, adapts itself to inequalities in the record surface and to angular variations with the sound box, maintaining its tangential alignment with each groove in the record. The rollers may be on one or both sides of the helical drive and on the same shaft as the worm wheel. In place of the guide rod pivoted to the sound arm pivot I may use a guide rod pivoted on the turntable spindle and passing through a hole in the control box.

The speed control exercises a braking action on the record-and steadies the linear speed, checking any tendency to increase or decrease that speed. It may be used without the usual governor of the motor or with it if the governor is allowed to revolve freely without thefriction-disc coming into action.

A practical embodiment of the invention Will now be described more particularly with reference to the accompanying drawings wherein v I Figure l is a sectional elevation of the roller and governor.

Figure 2 is a plan view of Figure 1. Figure 3 is a plan showing a guide rod and the variation of the angle between the speed control box and the sound-box for two different positions of the tone-arm.

Referring first to Figures 1 and 2, the roller 1 rests directly on the record 16 and connuunicates the motion of the latter through the shaft 2 andwornrwheel 3 to the governor spindle 5 is a collar fixed to the spindle at, and 6 is a collar attached to the friction disc 7 and which is also mounted on the spindle 4 but movable longitudinally on the latter. Weights 9 are carricd .by flexible devices, such as strips of spring steel, which connect collars 5 and 6. Thus as the speed of the spindle 4 increases the weights 9 are caused by centrifugal action to move radially of the spindle 4t and thus'draw the friction disk 7 toward thecollar 5 and into engagement with a fixed pad 8. The shaft 2 and spindle l are centred in ball bearings (not shown in the drawings) in the control box 10. This box is pivoted at 1O so as to permit the same to move vertically with regard to the sound box shown by Figure 3. The speed of the spindle 4 being frictionally controlled by the pad 8, the roller 1 can maintain only a certain degree of speed, which speed is transmitted from the disc; the latter endeavouring to rotate at its own speed actuates the roller which in turn strives to attain speed sympathetically, but is withheld by the governor and so reacts on the disc which has to conform to the setting oft-he governor.

The contacting periphery of the roller is of rubber or like material and has a fine helical thread cut on the surface thereof during the moulding or formation of the rubber and agreeing with the pitch of the grooves in the record. The roller will thus have a natural tendency to accompany the needle in its travel whether to or from the centre, and the helical thread will engage with and follow the direction of the grooves in the record and so prevent side-slip.

In Figure 3 there is shown a rod or wire 13 which acts directly on the box 10, by limiting its movement and guiding it along the record track. The control box 10 is pivoted at 10 to a member hinged at 10 to the llu sound box body to permit angular movement of the control box 10 relatively to the sound box 14: as the sound box moves toward the center of the record.

Figure 8 shows two positions or the control box 10, guide rod 13, sound-box M and tone-arm 15, and the variation of the angle between box 10 and sound-box 1%, when they are at the circumference of the record 16, and when they are near the centre. The rod 13 is pivoted at a point on the stone-arm standard or on the cabinet.

I claim:

1. The combination, with sound recording and reproducing machines comprising a rotating record, and a sound box adapted to travel over the record, a speed control support pivotally mounted directly on said sound box, a rolling member mounted to rotate in said support and to contact with the record and to be rotated thereby, a centrifugal weight governor mounted to rotate in said support and adapted to be rotated by said rolling member at a predetermined speed, and means adapted to cause the said support to vary its angular position with regard to said sound box as the sound box travels across the record. I

2. The combination, with sound recording and reproducing machines comprising a rotating record, and a sound box mounted on a pivoted support and adapted to travel over the record, a speed control support pivcontrol support with regard to the sound box as the latter travels across the record.

3. The combination, with sound recording and reproducing. machines comprising a rotating record, and a sound box adapted to travel over the record, a speed control support pivotally mounted directly on said sound box, arolling member mounted to rotate in said support and to contact with the record and to be rotated thereby, a centrifugal weight governor mounted to rotate in said support and adapted to be rotated by said rolling member at a predetermined and means adapted to cause the said vary its angular position with regard to aid sound box as the sound box travels across the record, and to retain the rolling member in a posit-ion substantially tangential to the sound line on the record.

In testimony whereof I have hereunto set my hand.

HAROLD ALFRED ROGERS.

speed, support to 

